Scoop-condenser apparatus



z 1931- H. F. SCHMIDT 1,797,841

SCOOP CCNDENSER APPARATUS Filed May 31, 1928 VOLUME INVENTORl-LEschmidl' Cl), V5. W

ATTORNEY WITNESS PatentedMah 24, 1931 mirnsnzr. somvrrnr, or LANSDOWNE,PENNSYLVANIA, AssIGivoRvro wnsrms sonsn ELECTRIC & MANUFATURING-COMPANY, A'CVORPOBATION. or PENNSYLVANIA I scoor-colvnnivsnaAPPARATUS I Applieationfiled May 31,

Thisinvention relates to scoop condensers and it has for an object toimprove the chiciency of condensers of this type.

In the operation or this class of equipment, it has been the practice toprovide auX- iliary circulating pumps for accelerating the rate of flowof the circulating water when after the main engines are reversed andafter the wash fromthe propellers becomes efiective' to oppose thecirculation which might otherwisebeproduced by the forward motion of theship. Also, after the vessel has lost its forward headway and is gainingheadway astern, the back pressure created by the wash from thepropellersand the astern motion of the ship is, likewise, efliective, either ingreatly reducing, or even in reversing the flow of circulating water.

conditions just described produce variations in-the dilferentialpressure across the condenser." WVhile an attendant may ascertainfrom'the vacuum gauge that the circulation should be improved, hehasnomeans of'determining the direction in which the circulating water may bepassed with the least resistance. Moreover, since, in. the reversal of aship, thelossof vacuum and also'the accumulation of aniexcessivepressureflin the condensers. mayvtake' place almostinstantaneousr 'ly,the only course. of procedure, which has beenconsidered safe, is foranattendant in charge of the auxiliary pump to see that this pump isoperatedlt'o capacity at the first indication of a falling, ofi oftheva'cuum.

"Consequently, merely reversing the circu lating pump will not overcomethese difficulties, since no means haveb'en provided for pump if it weredesigned to handle the full It will readily be seen, therefore,; thatthe 1928 Seria1No.2 81, 983. I g

ascertaining the, proper time to change the directlon of flow.

I Since the 'circ lating pump in the usual installations must befahle todischarge water against the bacl; pressure created" by theasterninotionof the shipand the wash'from thepropellers, an unduly largedriving turbine; woulc he required for the, circulating amountoffcirculating water 'required by the condensers,"However, the auxlllarycirculat-. ingjpumps are generally made of very much reduced capacityand power, and in the case of destroyers and high speed naval vessels, 9

great care has'to be exercised in going astern atfullpower,inview of therelatively small 7 capacity and power of the auxiliary circulat ingpump, to avoid building up anexcessive' steam pressure in the condenserwhen the vessel is coming to restur d l ,Furthermore, in some cases, theaniountpf steam required for operatingzthe circulating pump becomesquite large; Intact, the quanltity of steam requiredfor this purpose mayamount to as much, or more, than thatre: quired the main engines? It'1nay thus occur, that, in suddenly changing from for ward to aster-n,the auxiliary circulating pump throttlevalve may be opened so quicklythat the demand for steam by'the' circulating pump 'may cause areduction in the boiler pressure sufficient to interfere with themaneuvering of the mainfengines. On t-he other hand, if; advantage istaken of the ahead motion of the ship, or of the astern motion and theash of the propellers, a relatively small amount of poweriis suficientto handle tllGillll volume of'circulating water required;

: More particularly, therefore, an object of r my invention is toprovide .for assisting the flow of circulating water, in ascoop conkdenser,by means of fluidltranslating apparatus which is,prefe rably,reversible inure sponse to the attainment of predetermined difierentialpressures, whereby the translating forces developed bythe translatingapparatus may be combined, either with thetrans lating forces due to theahead motion ofthe ship,or with those due to the astern motion and tothe wash from the propellers, the par-. 100

ticular combination of forces depending, preferably, upon theattainmentof a pressure difi'erence which is suflicient to produce therequired flow through the circulating system.

This and other objects is effected by my invention, as will be apparentfrom the following description and claims taken in connection with theaccompanying drawings, forming a part of this application, in which'Fig. 1 is a diagrammatic view of apparatus'illustrative of principlesof my invention, and v, r

Fig. 2 is a graph showing characteristics of a pump which may be usedwith apparatus of the type described. i

In accordance with a preferredform of my invention, the fluidtranslating'apparatus takes the form of a propeller pump, which ismounted in one of the scoops,and which is adapted to be operated by areversible motor, such, for example, as a reversible turbine,

'or an induction motor. In this connection,

it is noted that my novel arrangement of condenser, scoop system andauxiliary circulat ing pump is disclosed and claimed in my copendingapplication, Serial No. 515,759, filed February 14:, 1931, entitledCondenser circu- -latin'g system and assigned to the WestinghouseElectric and-.Manufacturing Company.

The direction of rotation of the motor is controlled, preferably, by apiston in a work- The pressure cifi'erence across a 'manner similar 'tothe functioning. of a pilotvalve 1n a fluid pressure relay. Means areprovided for restraining the movement. of'the piston, and-hence, thereversal of the motor, until the proper pressure difference prevailsacross the propeller of the pump.

Means are arso provided for preventing the reversal of the motor due toa pressure difference,'whichthough of theproper value,

might be due to clogging ofthecirculating system, instead one areduction of speed, or to running'astern. Referring now to. the drawingfor a better understanding of 'my invention, I show a ships hull 10,having a bottom 11, and a condenser 12 supported in any suitable ma-nnerby the ships hull. The condenser is of the'scoop type and it hasconduit, orscoop portions 13 and 14: arranged at the forward and asternends, respectively, the conduit portion 13.terminating at its forwardend in projecting lip or scoop construction 15' of any suitabledesigm Inorder that the objection of loss of power and consequent possibleserious reduction of boiler pressure, .due to the necessity heretofore,.of overcoming the velocity head of coolingwater when running asterinmay.be'overcome, .I provide areversible propeller 17in the forward conduit13, the reversible propeller being, carried by a shaft 18, whoseouterend is connected to a suitablemotor, at

passages 22 20. In the form shown, the motor at 20, takes the form of areversible steam turbine, al-

though any reversible motor may be used for operated to supply steamthrough either'the passage 22 or the passage 23 so that the turbine maybe operated either in one direction or the other, I show pressureresponsive means for controlling such valves, this pressure responsivemeans preferably taking the form ofapparatus which is responsive to apredetermined differential pressure in either direction across thepropeller 17. To this end, I

peller 17, the other ends of these conduits being connected to thecylinder 29 adjacent to the endslof the latter, the clyinder 29contaming a piston 30'connected' to a rod 31, which cooperates with alever 32 for actuating the valves 24 and 25 in order that steam may besupplied alternatively through the and 23 to secure operation 01 theturoiue in either direction.

' In order that the lever 32 may be moved sufficiently in eitherdirection to fully close one valve and open the other, as well as toimpose sufficient resistance on the piston rod 31 so that the latterwill not be moved until a predetermined differential pressure isattained across the propeller 17, I provide a spring toggle mechanism, 33,which, not only serves to afford this resistance, but also secures apositive snap-overactionin either direction in orderto fully close onevalve and to fully open the other. Due to the resistance of the springtoggle mechanism, it is assured that minor fluctuations in differentialpressure across the propeller, such as may occur .When a ship is beingmaneuvered for docking,' shall not result in reversalof the tur hine. For example, the spring toggle-mechanism may be so designed that a speedof 10 any reason, the valves would come into opershow conduits 27 and 28opening into the conduit 13 at opposite sides of the proration andreverse the direction :of, rotation and flow through thecondenser.

The building up of pressureoin eXcess of thenecessa-ry 10. feet would becaused, either lay-reversal of, direction-of the ship, or' by theclogging ofthe condenser tubes with sea weed, or other foreign matter. 4

:It is further obvious, that should seaweed, fish, rubbisl1 ,':.or otherdebris be caught on the tube sheets, the reversal of flow will wash suchobstructionsoverboard and automatically keepthe condenser clean. v

Asshown on the drawing, the vessel, is proceeding-forward, or to theright, the scoop 13 beingthe vforward scoop. -Under these conditionsthe'velocity of flow through the conduit or scoop portion 13 isrelatively high and the pressure difference between the front and rearsides of thepropeller is relatively small. The piston 30 is at theleftendof its stroke in flthe cylinder 29, and although the pressureinthe. passage-'28 under these conditions is greater than that in thepassage 27, the difference of pressure across the propeller issolsmallasto be inefiectivefagainst the: toggle mechanisnnand as long as theseconditions prevail the toggle mechanism will holdthe piston 3Q in thisposition.

In thegraph shownin Fig. 2, the pressure volume characteristic and theefficiency curves for a propeller type pump are shown. vAt thepointtl-on the pressure volume. curve the pump is; operatingatitsmaximum efficiency.

This is, preferably, the point atirwhiclrthe pump is operating as shownin'the drawings for normal forward speeds oft'he'vesseL Since theordinates of the pressure-volume curve are the PIQSSLIIQ-dlffGTGDCBSacross the propeller, it will be'clear that as the quan-e tity orvolume, of water delivered decreases, the pressure difference willincrease. Hence, as the forward speed ofthe vessel is reduced, theforward scoop '13 becomesle'ss effective and "supplies a smallerquantity of water and the burden on the pump increases. It will be cleartherefore, that at some pointon the pressure volume curve, such as atthe point 42, :the pressure difference acrossthe ropeller will be greatenough to overcome theresistance iofi'ered by the toggle mechanism andto move the piston 30-to the right and thus, to-reverselthe pump.

It will also be obvious that the reversal "of the pump is effected,.when changing from astern to aheadoperatiomin the same manner as thatjust described, such reversal result-V ing in the various partsreturning to the positions in which they areshown on the drawing. i I

"It will be understood, of"course,'that at high speeds, very littleworlrneed be done by. the-pump and in fact at such speeds the'scoo-peffect may be so great that the flow of water will actual'ly'runthe'pumpyas a water turbine. Under these co'nditions,= the} press i suredifference across then-propeller would be svery smalland the togglemechanism would hold the piston 30. in'the proper position. A i a 'Inchanging from ahead to astern operation, a vessel may have considerableforward headway even after themain engines have beenreversed and afterthe wash from the propellers has become effective to oppose the, "flowof circulating water through the astern scoop .and through the condensertubes. Hence, itis desirable that the flow through the condenser tubesbe reversed before the vessel has completely lost its forward-headway,as otherwisethe circulating pump would have to oppose the pressure headdue to th wash from the propellers.

" It will be apparent that the apparatus thus far described iscapableofattaining these astern.

"With the apparatus thus far described, there is a possibility of thecirculating system becoming so clogged with dbris,and the like, and thusoffering s'uflicientresistance to the flow ofthe circulating water toproduce the pressure difference required to reverse the pump while thevessel isproceed ing forward under considerable headway.

Should this occur, the pump would be operat- 7 ing against the velocityhead due to the forward motionof'the ship. j

' In order to prevent an occurrenceof this kind, I connect the pistonrod 31 to the piston 23% in-theworking cylinder 36, The'actuating mediumis introduced and discharged 7 from the cylinder36 by m'eans of thePitot tubes 37 and 38, which extend through-the hull 1'1, tothe ports ofthe cylinder,the tube 37 being pointed forward, while'thetube 38 ispointed During'forward motion of the ship,

the velocity head of the waterwill be avail able through the tube 37tomove the piston 34jto the left and to'hold it-there until the speed isconsiderably reduced; Should the vesselbe proceeding astern, thevelocity head duetothe wash fromthe propellers and to the 'asternmotion-will act through the tube 38 to move thep'i'ston to the right andto holdit in this position."

I It'will be apparent, therefore, that a pressure difference due to theaccumulation of debris in thecirculating system, cannot effect'areversal' of the pump in suchja way as'to cause'it to oppose thepressure head due to any appreeiable'speed of the'ship; Moreover, shoulda pressure difference, due

tofclogging or the like, occur at a low speed i where thevel y head" s flit le. effect i he cylinder 36,- thereversal of the pump scoop typewherein the objection of the .cir-

culating pump opposing thevelocity head of coolingwater when runnmgastern is avoided, advantage being taken of the propulsion speed ineither direction to secure passage of coollng water through thecondenser in either direction, depending upon pressures prevailing atthe scoops. Another advantage of the present construction .is that thecondenser system may be readily evacuated of seaweed,

the condenser will be capable of producing the required vacuum under allconditions of operation.

In addition to producing the required vac uum under the variousconditions of service, my apparatus is arranged to operate with minimumconsumption'of power.. As previously pointed out, neither the directionof motion of a vessel, nor the point at which that direction isreversed,may be taken as an indication of the condition of flow in thecirculating system of a scoop condenser. For these reasons, it has beenthe practice to pro vide auxiliary circulating pumps of very largecapacity so that water may be forced through the tubes in the samedirection whether proceeding ahead or astern, the reason for thispractice being that regardless of which way the water is forced throughthe tubes, there is a pointat which the pump must be capable of opposingthe velocity head.

due to 'the motion ofthe vessel, since the apparatus of the prior art isnot adapted to 1 function in response to variations, or changes in theactual conditions of flow. Since my pumping apparatus is arranged tooperate in phase with any appreciable changein head, itwill be clearthat I may use a much smaller pump than has heretofore been consideredadequate, and consequently, I may thereby effect a saving in powerconsumption as well as in the first costof equipment. Furthermore, itwill be obvious that my pumping apparatus may be operated continuously,oronly at reduced speeds and when running astern.

lVhile I have shown my invention in but one form, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various changes .and modifications,

without departing. from the spirit thereof,

tions shall be placed thereupon as are imposed by the prior art or asare specifically set forth in the appended claims.

lVhat I claim is 1. The combination with a condenser of the marine typehaving conduit port-ions communicating with the ends thereof, apropeller arranged in one of the conduit portions, a reversible motorfor driving the propeller, and means depending upon the difierentialpressure across the propeller for controlling the direction of rotationof the motor.

:2. The combination with a marine condenser of the scoop type havingconduit portions communicating with the ends thereof, apropellerarranged in one conduit portion, a reversible motor fordriving. the propeller, conduits communicating with the conduitcontaining the propeller at each side of the latter, a pressureresponsive device connected to said conduits, controlling means for thereversible motor, and means for actuating the controlling means fromsaid pressure responsive device.

3. The combination with a marine condenser having cooling water conduitportions communica-ting with the ends thereof, a propeller arranged inone cooling water conduit portion, a reversible motor for driving thepropeller, passageways communicating with the cooling water conduitportion containing the propeller at each side of the latter, a cylindercommunicating with said passageways, a piston in the cylinder, andcontrolling mechanism for the motor operatively connected to saidpiston. r

4. The combination with a marine condenser of the scoop type havingcooling water conduit portions communicating with the endsthereof, of'apropeller'arranged in one conduit portion, a reversible motor fordriving the propeller, controlling'means for the motor, and meansresponsive to a predetermined differential pressure in either direc tionacross the propeller for rendering efiective the controlling means. i

5. The combination with a marine condenser and scoop means forcirculating coolingwatertherethrough, of auxiliary pumping means forcirculating cooling water through the condenser, means for reversing thedirectionof flow of the water clrculated by said auxiliary pump ngmeans, and means responsive to a characteristic of the water ofcirculation for controlling the direction of flow of thewaterscirculated by said auxiliary pumping means.

6. The combination with a marine condenser and scoop meansforcirculating cooling water therethrough, of auxiliary pumping means forcirculating cooling water through the condenser, means for reversing thedirection offlow of the water circulated by said auxiliary pumpingmeans, means responsive to a characteristic of the water ofcirculationfor reversing the direction of flow of the water circulatedby said auxiliary pumping means, and means for restraining thereversingmeans, whereby frequent reversals due to slight changes 1n thecharacteristic of the water of circulation are avoided.

7 The combination with a marinecondenser and scoop means for circulatingcooling Water 'therethrough, of an auxiliary pump for circulatingcooling water through the condenser, said auxiliary pump being redrivingthe propeller, and means responsive to a pressure characteristic of thewater of circulation for controlling the direction of rotation of themotor.

In testimony whereof, I have hereunto subscribed my name this 29th dayof May, 1928.

HENRY F SCHMIDT. V f

versible so as to effect :a direction of flow I through the condenser ineither an ahead or an astern d1rection,'and means responsive to acharacteristic of the water of circulation for controlling the pumpingdirection of the for circulating cooling water through the condenser,said auxiliary pump being reversjss ible so as to effect a direction offlow through the condenser in either an ahead or an astern direction,means'responsive to a characteristic of the water of circulation forcontrolling the pumping direction of the auxiliary pump, and means forrestraining the reversing movements of the auxiliary pump, wherebyfrequent reversals due to slight changes in the characteristic of thewater of circulation are avoided.

9. The combination with a marine condenser, of a reversible pump forcirculating cooling Water therethrough in either an ahead or an asterndirection, and means responsive to a characteristic of the water ofcirculation for controlling the pumping direction of said pump.

10. The combination with a marine condenser, of a reversible pump forcirculating" cooling water therethrough in either an ahead pump, andmeans for restraining the reversing movements of the pump, wherebyfrequent reversals due to slight changes in the r characteristic of thewater of circulation are avoided.

11. The combination with a condenser "of the marine type having conduitportions communicating therewith for supplying cooling water thereto, ofa propeller arranged in one of the conduit portions for effecting acirculation of cooling water through the, condenser, a reversible 7motor for driving the propeller, and means responsive to acharacteristic of the water of circulation for controlling the directionof rotation of the motor. r

12. The combination with a condenser of I the marine type having conduitportions communicating therewith for supplying cooling water thereto, ofa propeller arranged-in one of the conduit portions, areversible motorfor

